Fluke 440RF User Manual
Victoreen® 440RF/D
Low Energy RF Shield Survey Meter
March 2005
Manual No. 440-500-1 Rev. 5
©2004, 2005 Fluke Corporation, All rights reserved. Printed in U.S.A.
All product names are trademarks of their respective companies
Operators Manual
Fluke Biomedical
Radiation Management Services
6045 Cochran Road
Cleveland, Ohio 44139
440.498.2564
www.flukebiomedical.com/rms
Table of Contents
Section 1: General Information................................................................................... 1-1
1.1 Product Description ..................................................................................... 1-1
1.2 Specifications............................................................................................... 1-2
1.3 Getting Started............................................................................................. 1-3
Section 2: Operation.................................................................................................... 2-1
2.1 Controls and Indicators................................................................................ 2-1
2.2 Power, Battery Check and Range Changing ............................................... 2-1
2.3 Instrument Positioning and Scanning .......................................................... 2-2
2.4 Chamber Location ....................................................................................... 2-6
2.5 Measurement of Exposure Rate .................................................................. 2-6
2.6 Source Geometry Corrections ..................................................................... 2-7
2.7 Chamber Corrections................................................................................. 2-12
2.8 Low Level Measurements .......................................................................... 2-13
2.9 Operational Check Source......................................................................... 2-15
Section 3: Theory of Operation................................................................................... 3-1
3.1 General ........................................................................................................ 3-1
Section 4: Circuit Description..................................................................................... 4-1
4.1 Ion Chamber ................................................................................................ 4-1
4.2 Probe ........................................................................................................... 4-1
4.3 Analog Board ............................................................................................... 4-1
4.4 CPU Board................................................................................................... 4-3
4.5 Switchboard ................................................................................................. 4-3
4.6 Motherboard ................................................................................................ 4-3
4.7 Analog Meter Readout................................................................................. 4-3
4.8 Meter and RF Filtration ................................................................................ 4-3
Section 5: Maintenance, Repair and Calibration....................................................... 5-1
5.1 Maintenance ................................................................................................ 5-1
5.2 Battery Replacement ................................................................................... 5-1
5.3 Repair and Calibration ................................................................................. 5-1
Section 6: Replacement Parts .................................................................................... 6-1
6.1 Replacement Parts ...................................................................................... 6-1
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General Information
Product Description
Section 1
General Information
1.1 Product Description
The Model 440RF/D Low Energy RF Shielded Survey Meter (Figure 1-1) is designed to measure low
intensity gamma or x-ray radiation fields. In addition, it can be utilized as a beta detector. Response to
gamma energy over a range of 6 keV to 1.2 MeV is achievable in fields as low as 0.1 mR/h. Upper limit
measurable exposure rate is 100 mR/h.
The instrument is especially valuable when used for x-ray leakage detection, chiefly in the vicinity of
electronic equipment with large electromagnetic fields.
The Model 440RF/D is a portable RF shielded, radiation exposure rate measuring system. The
instrument is composed of a detector (or transducer) and electronics which provide amplification, meter
response and computer interface (when used with a communicator device).
1
The detector is a guarded, unsealed air ionization chamber. The small DC signal produced by the ion
chamber is monitored by a sealed, evacuated preamplifier and is processed using the latest CMOS
microprocessor and support chip technologies.
The processed signal is then passed through a transistor-pulsing circuit to produce a standard analog
meter readout.
Using the communicator option, data entry verification, test, or calibration can be performed. In addition,
the instrument can be adjusted to meet environmental factors.
Figure 1-1. Model 440RF/D Low Energy RF Shielded Survey Meter
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Operators Manual
1.2 Specifications
Full Scale Range Model 440RF/D:
Radiation Detected
Operating Range Model 440RF/D: Exposure rate in five overlapping ranges:
Energy Response X and Gamma: + 10% from 12.5 keV to 42 keV effective, with
Insensitivity RFI: Operates properly in 10 mW/cm2 fields
Accuracy
Response Time Range Response Time
Ion Chamber Chamber Window Area: 10 cm
Case Window
Batteries
Weight
Dimensions (H x W x L) Unit: 8 in (includes handle) x 4 7/8 in x 10 7/8 in
Environmental Dependence Operating Temperature: -4° F to 104° F (-20° C to 40° C)
0 to 1, 0 to 3, 0 to10, 0 to 30 and 0 to 100 mR/h
Model 440RF/D-SI
0 to 10, 0 to 30 and 0 to 100, 0 to 300 and 0 to 1000 μSv/h
Gamma, x-ray, and beta
0 to 1, 0 to 3, 0 to 10, 0 to 30 and 0 to 100 mR/h
Model 440RF/D-SI: Dose equivalent in five overlapping
ranges: 0 to 10, 0 to 30, 0 to 100, 0 to 300, 0 to 1000 μSv/h
a maximum peak of + 40% in the medium energy range.
Beta: Energies above .15 MeV
Magnetic: Operates properly in a 200 gauss field
Maximum instrument inaccuracy, exclusive of energy
dependence, is less than +
10% of full-scale indication.
0 to 1 mR/h (0 to 10 μSv/h) 7 seconds
0 to 3 mR/h (0 to 30 μSv/h) 7 seconds
0 to 10 mR/h (0 to 100 μSv/h) 5 seconds
0 to 30 mR/h (0 to 300 μSv/h) 5 seconds
0 to 100 mR/h (0 to 1000 μSv/h) 5 seconds
2
Volume: 60 cc
Chamber Window: Approximately 1.5 mg/cm
2
aluminized
mylar
Dimensions: 2.5 in (6.4 cm) long; 1.5 in (3.8 cm) diameter
13 mg/cm
2
magnesium
Three 9 V alkaline transistor batteries for the electronics (9 V)
and two 9 V alkaline transistor batteries for the chamber (-18
V) provide over 200 hours of continuous operation.
6 lb, 6.5 oz (2.9 kg)
(20.3 cm x 10.4 cm x 25.7 cm)
Display: 3.7 in (9.5 cm) Meter scale, marked 0 to 3 and 0 to
10
Relative Humidity: 0 to 95% non-condensing
1-2
General Information
Getting Started
1.3 Getting Started
Receiving Inspection
Upon receipt of the unit:
1. Check the shipping carton(s) and their contents for in-shipment damage. If damage is evident, file
a claim with the carrier and contact Fluke Biomedical, Radiation Measurement Services at
440.248.9300 immediately.
2. Check that all items listed on the packing slip are present and in good condition. If any items are
missing or damaged, contact Fluke Biomedical.
Storage
If the unit is to be stored prior to use, pack it in the original container(s) if possible, and store in an
environment free of corrosive materials, fluctuations in temperature and humidity, and vibration and
shock.
Routine Cleaning
Do not immerse the Model 440RF/D or Model
440RF/D-SI. The unit is not waterproof. Liquid
could damage the circuits. The unit should be kept
clean and free from dirt and contamination. The unit
may be cleaned by wiping with a damp cloth using
any commercially available cleaning or
decontaminating agent.
NOTE
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Operators Manual
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Operation
Controls and Indicators
Section 2
Operation
2.1 Controls and Indicators
Function/Range Switch
Function/Range Switch positions include OFF, BAT, 100, 30, 10, 3 and 1 (Model 440RF/D) and OFF,
BAT, 1000, 300, 100, 30 and 10 (Model 440RF/D-SI). The rotary switch is located below the handle. It
turns the instrument OFF, provides a battery check function, and provides five operating ranges in mR/h
or μSv/h, depending on user preference. The BAT position is also used with the communication option.
Refer to Specifications, Section 1-2 for a list of operating ranges.
Zero Adjust
The Zero adjust, a screw centered just below the meter scale, zeroes the meter needle.
Meter
A panel meter, located on top of the instrument, displays the exposure rate (mR/h), dose equivalent rate
(μSv/h), or battery condition.
2
Check Source
The check source, a hexagonal spring-loaded rotary switch positioned next to the chamber, verifies
instrument operability.
2.2 Power, Battery Check, and Range Changing
A single rotary switch, located beneath the carrying handle provides function/range capability. In the OFF
position, the 9 V electronic power supply is disconnected. The switch should be returned to the OFF
position whenever the instrument is not in use to extend the battery usage period and to prevent possible
damage to the battery compartment due to leaking or spent cells. Any other switch position will cause full
battery current drain. If the instrument is placed in operation after a period of idleness, place the
function/range switch in the BAT position and remain there. The function of the BAT position is to monitor
the condition of the 9 V electronic supply and the -18 V chamber supply. This is accomplished through
measuring the voltage (using the microprocessor) provided by the divider circuits directly across the
battery supplies.
If both sets of batteries are at the voltages required for operation when the instrument is placed in the bat
position from the OFF position, the meter should indicate full scale (9 V electronic supply), then drop to
approximately half-scale (-18 V chamber supply), then return to the full scale position. If the instrument is
in operation and battery check is performed, the meter will just indicate a full-scale reading. If either set of
batteries is not at the voltage required for operation, the meter will drop to 0 V.
If the meter reads 0 V in the bat position, remove the batteries (one set at a time) and test them using a
voltmeter to determine which batteries are bad. Replace the complete set for chamber voltage or
electronic supply once the batteries have been located. Refer to Figure 2-1 for battery compartment
location.
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Victoreen 440RF/D
Operators Manual
Once the battery check has been successfully completed, rotate the function/range switch to the first
exposure rate range (100 mR/h) or dose equivalent range (1000 μSv/h). If the instrument has just been
turned on, there may be an upscale indication on this range, but it should decay rapidly. When the
indication on this range is, or has decayed to, less than one-third of full scale, switch to the 30 mR/h (or
300 μSv/h) range. Continue switching ranges until a steady indication greater than one-third full scale, or
until the 1 mR/h (10 μSv/h) range is attained. If the instrument has not been in use for some time, this
procedure may take a few minutes.
Series 9 V – 18 V Chamber
Voltage – Replace Both
Paralled 9 V for 9 V Electronics
Supply – Replace all Three
Figure 2-1. Exposure Rate Measuring System 440RF/D Battery Compartment
If the instrument is brought closer to a radiation source, or if radiation is intensified until the meter needle
pegs above full scale, the function/range switch can be rotated to less sensitive operating positions. To
enable accuracy, set the function/range switch so that the maximum on-scale indication is visible.
2.3 Instrument Positioning and Scanning
In general, after warm-up and range selection, the measuring system is placed is some specific location
and attitude to obtain a reading. Operator knowledge of radiation source locations, special geometry
applications, physical placement problems, etc., will affect exactly how and where the instrument is
positioned. Because the instrument’s low energy response is best when photons enter the case through
2-2
Operation
Instrument Positioning and Scanning
the magnesium window, an operator should keep the window facing the field of increasing intensity (or
toward the source).
The instrument responds to the effective exposure rate or dose equivalent rate averaged throughout the
chamber volume. An exposure rate or dose equivalent rate 10 or 100 cm away cannot be predicted
without knowledge of the shape, direction, and contours of the radiation field involved. If this concept of
measuring a local field, rather than a general area, is remembered, confusion can be avoided.
Operator knowledge regarding the location of radiation sources can be divided into several classifications
which include precise location, general vicinity, and no specific location. Each classification requires a
specialized approach.
2
Precise Location
When positioning the instrument in a field where a nominal indication will occur, no position adjustments
are necessary. When placing the instrument in a field where maximum indication is desired, minor
position adjustments may be necessary.
General Vicinity
A small amount of careful scanning, less than a few square feet, can be employed so that a small
indication will be visible on the scale and so that fatigue will not occur. See Figure 2-2. Maximum scan
line speed should be between 2 and 4 feet/minute depending upon how low the source intensity
encountered.
The scanning motion should be slow, smooth, and uniform. If any upscale indication is encountered, the
scan should be stopped immediately in order to determine whether the instrument detected a cosmic ray
or a tiny intense beam.
NOTE
Scanning should be performed with minimum
jostling or jarring of the instrument, particularly
when a low exposure rate or dose equivalent rate is
underway.
No Specific Location
Scanning of large areas at low exposure or dose equivalent rates is not recommended for this instrument.
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Operators Manual
1 ½ in.
Maximum
Line Step
Figure 2-2. General Vicinity Scanning
2-4
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